It is customary, in the marketing of carpet, to display samples, usually in the form of, for example, thirty-two inch by thirty-two inch squares contained in a sample "book." In order that fraying of the samples may be minimized and also to present a neat and finished look thereto, it is generally the practice to bind the edges of a sample with cloth tape which is stitched to the edges to make a neat and fray-proof border extending along the entire periphery of the sample.
It is often the case that the individual samples are cut from a carpet roll and the cloth tape is sewn onto the edges by an operator controlled sewing machine, with the operator guiding the sample and feeding the tape onto the edge manually. When one edge of, for example, a rectangular sample is completed, the operator rotates the sample ninety degrees and continues sewing the second edge. This requirement that the sample be rotated at the proper time and to the proper orientation requires a degree of skill and a high degree of concentration on the part of the operator. In a mass production environment, such requirements can be both stressful and tiring, leading to error and consequent wastage. The edging procedure continues until all four edges of the sample have been trimmed with the tape, whereupon the operator cuts the supply tape, staples or sews any dangling end of the tape to the sample, and removes the sample from the machine. Because the carpet material is usually fairly heavy and stiff, the entire process can be quite tiring for the operator in addition to being slow and, of course, labor intensive.
The prior art is replete with machines and apparatus for automating the process of trimming and binding the edges of fabric pieces. For example, there is shown in U.S. Pat. No. 5,018,462 of Brocklehurst an apparatus for finishing the edges of flat soft textile products, such as wash cloths and the like. The Brocklehurst apparatus comprises a transport plate which bears against the cloth piece being edged and moves it into a sewing machine in response to a first sensor being covered. As the trailing edge of the piece passes over and uncovers a second sensor or detector, the transport plate rotates thereby rotating the workpiece through, for example, an angle of ninety degrees, thus covering the first and second sensors, and the workpiece is advanced by the plate until the second sensor is again uncovered. The Brocklehurst arrangement cuts an edge in the material and immediately thereafter stitches the cut edge around the periphery of the workpiece.
Other prior art arrangements utilize sensors to detect when to rotate the workpiece, such as shown in U.S. Pat. No. 4,722,290 of Manuel et al., which has the sensors placed on the sewing machine, U.S. Pat. No. 4,688,499 of Moore et al. which trims the edge of the workpiece prior to sewing an edging tape thereon, and rotates the equivalent of a transport plate to rotate the workpiece, sensors being used to ascertain and control the correct alignment of the workpiece; and U.S. Pat. No. 3,970,017 of Babson et al., which trims the material prior to edging, and utilizes pneumo-electric sensors to govern the operation. The workpiece is turned by means of a work swinging finger which moves in an arcuate slot. Other prior art patents which utilize sensors of one form or another to start, rotate the workpiece for sewing around the corner, and to stop the machines are U.S. Pat. Nos. 4,685,408 of Frye, 4,776,579 of Romand, and 4,601,249 of Frye. All of the aforementioned patents disclose apparatus for edging soft materials such as towels, wash cloths, and the like, which are relatively thin and flexible. The Moore et al. patent treats of throw rugs and other piled materials, which are similar to towels and the like in their softness and flexibility.
The problems concomitant with edging relatively heavy, stiff, and heavily piled materials are not addressed in the foregoing prior art patents, and the arrangements they disclose will not, for a number of reasons, overcome these problems.
A carpet sample which has been cut from a roll of carpet, for example, is characterized by a relatively stiff backing and a heavy pile. Quite often the pile will overlap the backing at the edges of the sample, so that the use of detectors to detect the edge of the sample will often result in the detection of the edge of the pile resulting in a false reading, and the sewing operation will, where edging tape is used, stitch the tape to the pile and not the backing, thus producing an edge that is impermanent and easily pulled apart. Because the carpet samples are individual pieces and not cut from a supply roll adjacent the machine, as shown in the Brocklehurst and Moore et al. patents, for example, unless they are to be conveyed to the machine on a long conveyor, they must be stacked in a bin or hopper at the input end of the machine. The problem then becomes one of removing a carpet from the hopper and placing it on the bed of the machine. The topmost sample cannot simply be slid off of the next lower one because of the heavy pile's resistance to such movement, thus it becomes necessary to lift the sample out of the hopper and place it on the machine bed. The prior art references do not deal with these problems, nor do they disclose any apparatus that might readily be adapted to the solution thereof.